2. speakers
  3. 1262354411

Kharma ceramic blow up

Has this happened to anyone?

I went to listen to the Kharma Exquisite Reference today paired with Soulution preamp, Soulution monoblocks, and the dCS Scarletti stack. I really enjoyed it until I put in Bela Fleck's "Flight of the Cosmic Hippo" track #4 which is very bass punchy/heavy.

The ceramic midrange proceeded to blow up BOOM and shatter! Is this common with ceramic midranges? I mean the whole driver literally blew up and shattered into pieces.

Usually a speaker blows up because of amplified distortion which causes the speaker piston movement to become non linear, but I highly doubt the Soulutions or dCS somehow caused this.

Nothing against Kharma, as maybe this was a one off thing. I did really like this setup though. The music was beautiful until it happened. I've been listening to setups from Rockport Altairs, Wilson Maxx3's, TAD Reference 1, and now today the Kharmas.

Should I be wary of about this? I don't want to spend so much money and have problems like this. Do you think this was just a one-off? Again I thoroughly enjoyed the Kharma's until then (but still needed to listen longer to get a better sense of the speakers).

Cheers.
changster
rtn1
535 posts
 
Accuton/Thiel makes thousands of ceramic drivers each year for dozens of speakers. What is particular about Kharma that makes them susceptible to failure? Is it cross-over design or in-house modifications?

I would not jump to the conclusion that this is an inherent property of ceramic drivers at all. We are dealing with pure anecdote, and no one has mentioned any other speaker. Even if someone did, it still would not necessarily indicate a systemic design flaw. I would agree that what Agyro dealt with from Kharma is absurd and absolutely unacceptable.

On another note, many drivers, regardless of material, may fail under the correct (?incorrect?) conditions. They just do not make such a dramatic statement. Leave your speaker grills on, folks, or wear protective goggles.
anupmc
21 posts
 
I've had the same thing happen with my Kharma too, but I believe there are a couple of mitigating factors...

1) Kharma midrange drivers are virtually connected directly to the Amp (whereas the bass and tweeter drivers are linearly crossed-over). This makes the fragile ceramic cone on the midrange driver relatively exposed! Conversely though, its the very reason why the Kharma midrange sounds so fantastically neutral and natural.

2) The Kharma drivers need plenty of run-in before playing at high SPLs. I'm guessing that pair of Exquisite Reference units weren't thoroughly run-in. With high SPL and a dynamic track, I'm not surprised the cone broke up, probably like a crushed egg-shell :)
bwcanuck
30 posts
 
Speakers don't blow up because of "amplified distortion which causes the speaker piston movement to become non linear" but rather clipping allows power to defeat the crossover point and burn the fine coil and leads, similar but different to how a diode only allows power to continuously flow in one direction but will allow pulsed transients to flow in the opposite direction. This illustrates the "minor exception" factor.

Drivers exploding on the other hand usual do so if they are of a high hardness material and resonance node is excited at high power, or if their excursion is exceeded and the air load or suspension puts the diaphragm under additional stress. The T&P drivers all have notable resonance nodes as dictated by the material though they are mostly outside their intended crossover range. The amplifier may have been responsible possibly too.
fplanner2010
283 posts
 
Speaking of "ceramics", heard the latest Marten speakers with 4 built-in passive rear woofers in the Vitus room at CES. They are ridiculously expensive in the US, but contributed to one of the best sounding rooms at the show, IMO. They were being driven very well by a higher current, lower wattage Vitus integrated amp and they were absolutely great, IMO.
shadorne's avatar
Ag insider logo xs@2x
shadorne
7,477 posts
 
Changster,

Just get a pair of ATC 100ASL and you won't be blowing midrange anymore.

There is a good reason why large three ways with the accuton mid use TWO midranges!
More to discover